Move data classes into appropriate repositories

This pull request moves the data classes found in ```clawdata.py``` into the appropriate other repositories.  This has the advantage that if the data objects are changed only one repository needs to be touched to update both the Fortran and Python.  Some updates to the data objects being touched including a 1-to-1 relationship between written files and data classes have also been added (e.g. the ```GeoclawInputData``` class wrote out a number of different files).

Associated pull requests at 
* clawpack/clawutil#36
* clawpack/visclaw#32
* clawpack/amrclaw#34